v1-4: Paul's disappointment, wanting to present every man mature in Christ Jesus (Col 1.28), there was a distinct lack of such maturity.

v1: The Corinthian Christians were not spiritual, but carnal, having failed to mature. But they were still brothers, and still loved and cared for, although demanding support and prayer. To be "carnal" means red, like Adam/Edom, human and worldly, acting in the character of natural humanity, "acting like mere men" (v3). True Christian behaviour is not like ordinary human behaviour.

v2: It is to be expected that Christians need "milk" initially, as a baby does (see 1 Peter 2.2); but the clear expectation is of growth and progress to maturity, therefore needing "solid food". See also Heb 5.12. Paul does not hide his disappointment. Christian leaders have a responsibility to promote growth, but each of us shares that same responsibility to seek personal growth.

v3: The evidence of a lack of maturity; envy, strife, jealousy; such things, whilst being part of human life, are not acceptable amongst Christians.

v4: The problem of hero-worship, of Paul the wise, and Apollos the eloquent. They measured others by human standards, which encouraged envy, produced strife, and led to division. The exaltation of human leaders is very dangerous.

v5-7: The servant of God is a team player, working especially with God Himself. What is important is not what the individual does, but what God does. We are required to fulfil the tasks given to us by God, and the foundation of that work is in Christ (v11).

v8-10: United in service; we play different roles (John 4.36-38), but all serving the same God, all part of God's building.

Each one of us is responsible before God for how we build, and accountable to Him. This is a serious issue, and we dare not be complacent.

Paul refers to his own special role as an apostle, a master builder, laying foundations; see Eph 2.20.

v11: Jesus Christ the only foundation; in practice we are to make Him the most important, central, all in all, in our lives; the effect will be that His character will be formed in us. Similarly, our doctrine must be centred in Him, not in other issues. We are fools if we do not build on Him.

v12-15: We are held responsible for how we build. The "Day" will bring to light what we have built; the testing will be by fire, which will burn up the dross. Terry Virgo refers to a ‘meticulous inspection’ (God’s Lavish Grace, p70).  The Lord Jesus observed those putting their gifts into the treasury (Mark 12.41-42), noting the motivation of the givers. There are examples of the Lord Jesus testing the motives of the churches at Ephesus (Rev 2.4-5) and Laodicea (Rev 3.15-16).

This is not purification, for Christ has purified us already, nor judgment, for Christ has borne our judgment.

v16-17: The picture of building and foundation is continued with the temple; the place where God dwells by His Spirit, a place designed for the worship and service of God. The teaching here is that the church in Corinth was the temple; but the temple can be defiled by our bad attitudes and unfaithfulness. This provides further reason to be responsible in how we live.

Jonathan Edwards; ‘The Spirit of God is given to the true saints to dwell in them as His proper lasting abode; and to influence their hearts, as a principle of new nature or as a divine supernatural spring of life and action The Scriptures represent the Holy Spirit not only as moving, a)nd occasionally influencing the saints, but as dwelling in them as His temple, His proper abode, and everlasting dwelling place.’ (Religious Affections)

v18-20: Avoid the wisdom of the world; the godly man will be dismissed as a fool, and the ungodly honoured. But we must learn to see things as God sees them.

v21-23: Set our sights high! In Christ, we are inheritors of "all things", so it is folly to set our affections upon another, or to pursue human wisdom. Paul points his readers to a massive inheritance in Christ, which we can enjoy, or we can miss.